Sand and mud separator and mixer for well drilling



Sheec s-Sheet l JVVENTDJL JI'CHRISTENSEN April 27, 19371.

c, T. CHRISTENSEN SAND/AND MUD SEPARATOR AND MIXER FOR WELL DRILLINFiled April 15 1955 April 1937. c. T. CHRISTENSEN 2,078,752

SAND AND MUD SEPARATOR AND MIXER FOR WELL DRILLING Filed April 13, 19332 Sheets-Sheet 2 JVENTUJL 5 2521515 TENSE'N :ZTTOENEys Patented Apr. 27,1937 UNETED STATES PATENT QFFEQE SAND AND MUD SEPARATOR AND MIXER FORWELL DRILLING sen Application April 13,

3 Claims.

My invention relates to a separator and method of operation inseparating the sand or gritlike material from the slushing mud, such asused in deep well drilling or boring. In the hydraulic type of wellboring, a slushing mud, the mud being sometimes weighted, is forced tothe bottom of the hole at the cutting bit and carries the cuttings,which are usually ground to sand of different degrees of thinness, tothe top of the well. My invention pertains to a machine and method forseparating this sand from the mud so that the mud may be used forsubsequent drilling operations.

An object and feature of my present invention is the employment ofelongated channels, parts of which have a fiat floor and the dischargeparts a common sloping floor through which the mud with the sand maycirculate from one channel to another, and in these channels the sand isallowed to settle to the bottom. In my machine and method the sand isscraped from the bottom in such a manner that there is but littleagitation of the mud and, hence, a stirring of the sand into the mudagain or a stirring which would still hold the sand in suspension. Thesand, being heavier than the particles of the mud, separates to thebottom if the flowing mud is not agitated to too great an extent.Therefore, it is necessary to remove the sand from the flat and inclinedfloor of each channel in such a manner that the mud is not undulyagitated and that the sand scraped along the bottom is not agitated andagain mixed with the mud.

To efiect the removal by a scraping action of the sand, I employ endlessbelt type of scrapers, these having scraping blades which are drawnalong the fiat bottom and up the inclined end of each channel.

Another object and feature of my invention is forming a separator in atank, this tank having longitudinal partitions. The mud flows in thefirst channel at the end opposite the inclined discharge floor for thesand and may flow into the second channel before reaching the dischargeend. There is a reverse flow of the mud through the second channel, andby a lateral opening the mud flows into the third or last channel. Thischannel has a partition entirely separating it from the second and firstchannels except for 5 the inlet at the end remote from the inclinedfloor.

One of the objects and features of the above construction is to employ aWashing spray and a deflecting partition to maintain the washing waterseparate from the mud, to a certain extent.

1933, Serial No. 665,923

The washing water is discharged on the sand being moved up the inclineddischarge floor by the blades of the endless belts, and this water flowsunderneath the partition, giving a slight circulation counter to that ofthe flowing mud, and this maintains the mud slightly thinner adjacentthe discharge end than at the other portions of the tank.

Another feature of my invention is having the deflecting partitionsspaced parallel to the flat and inclined section of the floor andextending from side to side of the tank, and also in having a dischargeoutlet from the third channel positioned above the horizontal section ofthis deflecting partition.

Another detailed feature of my invention is the employment of transversebafiles which extend below the level of the mud in the tank andterminate above the lower run of the endless belt. These partitions do:not extend up the sloping inclined floor part of the tank.

My invention is illustrated in connection with the accompanyingdrawings, in which:

Fig. 1 is a plan taken in the direction of the arrow I of Fig. 2.

Fig. 2 is a longitudinal section on the line 22 of Fig. 1, in thedirection of the arrows.

Fig. 3 is a transverse section on the line 3-3 of Fig. 1 in thedirection of the arrows.

Fig. 4 is a transverse section on the line 44 of Fig. 2 in the directionof the arrows.

In my invention I employ a tank I I which has side walls I2 and I3, anend wall I4, and a flat floor I5. At one end there are inclined sidewalls I5 having a notched construction I? fitting on the corner formedby the top of the side walls I2 and I3 and the end I8 of such walls. Inaddition, there is a sloping brace I9 secured to the inside of each wallI2 and I3. Crossbeams 26 extend between the braces I9, and along thesebraces and the crossbeams there is a sloping discharge floor 2I. A shortcurved section joins the sloping and the flat floor section I5.

A first partition 23 extends from the end I4 longitudinally of the tankand terminates at 24. A second partition 25 is spaced from the end I4 bya flow opening 26 and extends the full length of the tank, terminatingat 2?. If this partition should be formed as high as the side walls I2and I3, or if it is built of lesser height, it may terminate short ofthe end I8 of the tank, and its end 21 conforms to the sloping floor 2|.Cross boards 28 and 29 extend across all of the partitions between thesides I2 and I3.

A deflecting partition designated by the assembly numeral 30' has a flatsection 3| parallel to the fiat floor I5 and a sloping section 32 whichis spaced from the sloping discharge floor 2| but need not be parallelthereto. On account of the partition 25 extending up the sloping floor2|, the deflecting partition is formed in one part with the edgesfitting in grooves 33 in the partition 25 and the side wall I3. (NoteFig. 3.) The other section of the deflecting partition extends from thepartition 25 to the wall I2 and has a notched-out section 34 at the end24 of the partition 23. This deflecting partition terminates at itsupper edge at 35 and at its lower edge at 36.

A spray pipe 31 extends across the-tank between the walls I2 and I3 andabove the partition 25. This may be connected to a source of watersupply and has spray jets 38 discharging downwardly on the slopingdischarge floor 3| above the upper end 35 of the deflecting partition33. The purpose of this is described hereinunder.

The endless belt or conveyor system utilizes a main drive shaft 39 whichis journaled in the side walls I2 and I3 and has a water tight packingtherein. An idler shaft 40 is located adjacent the end I4 and a secondidler shaft 4| adjacent the upper end of the inclined discharge floorstructure. The shaft 40 is journaled in the opposite sides I2 and I3 ofthe tank and the shaft in the sloping sides I6. These shafts are allprovided with sprocket wheels 42. There are three of these sprocketwheels on each shaft. A first sprocket chain 43 operates in the channel44 formed between the wall I2 and the partition 23; a second chain 45operates in the second channel 46 between the partitions 23 and 25; athird chain 41 operates in the channel 48 between the partition 25 andthe side wall I3. Each of these conveyor chains has a series of scraperblades 49, these blades being arranged so that on the lower run of eachconveyor chain they scrape the sand along the fiat floor I5 of eachchannel toward the inclined floor and upwardly along the inclined floor2| to discharge at the discharge end 50 of the machine. The distancebetween the blades 49 is released for the first chain 43 operating inthe first channel 44; the spacing is greatest on the chain 41 operatingin the third channel 48; the spacing intermediate in the center channel.The purpose of this spacing is hereinunder detailed.

An electric motor 5| is indicated as having a drive connection 52operating the power shaft 39 and, hence, by means of the sprockets 42conveying motion to the main shaft 39 and moving all of the conveyors atthe same speed.

The slushing mud is fed into the tank through an inlet pipe 53 or thelike at the end of the first channel 44 adjacent the wall I 4. The flowof the slushing mud is gradually along this channel in the direction ofthe arrow 54. There is then a reverse flow in the direction of the arrow55 from the end 24 of the partition 23. The reverse fiow continues inthe direction of the arrow 55 in the second channel 46. There is anotherreverse flow indicated by the arrow 51 through the flow passage 26 andthen longitudinally in the direction of the arrow 58 in the thirdchannel 48 to a discharge trough 59. This trough fits in an opening Gilin the side wall I3.

A series of baflle plates 6| extend'between the outside Walls and thepartitions and for the channel 46 between the two partitions. On accountof the endless chains each forming a triangular path, some of thesebafile plates, such'as 62, must be of decreased height to allow thelower run of the endless chains to pass over. Therefore, should thelevel of the slushing mud be raised to increase the flow, certain of thebafiles may be completely immersed but the major number of the baillesextend above the liquid level of the mud. Therefore, the mud must flowdownwardly on the face of each baflle and underneath. This gives adownward movement to any sand held in suspension in the mud and tends toaid the separation of the sand and the mud, the sand being deposited bygravity on the fiat bottom floor I5 and a portion, possibly, on theinclined fioor 2|.

The method of operation and functioning of my invention is substantiallyas follows:

On account of a continuous infeed of mud with the sand incorporatedtherein at 53 at the intake end of the first channel 44, the mud mustfiow slowly longitudinally of this first channel, the fiow beinginterrupted by the bafiles. During this flow the scraper blades on thefirst chain d3 have their under run moving in the direction of the fiowof the mud. I find it desirable to have the speed of the belts quiteslow and not more than about three feet per second. This appears toavoid undue stirring of the sand deposited again into the mud and also astirring action of the mud which will still hold the sand in suspension.In the first channel, on account of the mud and the endless conveyor ofblades moving in the same direction, there is but little agitation ofthe sand and mud. Hence, the sand deposited on the fiat fioor is readilyscraped longitudinally of this floor and upwardly of the sloping orinclined fioor 2|, the sand being discharged.

over the end 50. This sand is found to be usually of coarsest grain andheaviest. In the reverse flow channel 56 the fiow of the mud is in acounterdirection to that of the scraping blades in the lower run of theendless chain 45. Even in this case the flow of the mud as a whole is socomparatively slow that there is but little agitation of the sand andmud and this second conveyor removes sand of an intermediate degree offineness. In the third channel 48 the direction of movement of theflowing mud and the endless conveyor chain is in the same direction.

The function of the sprayer jets through the spray pipe 31 is to flowclear water on the sand being conveyed up the inclined floor 2|. Thisspray removes mud which might be adherent to the sand and thus cleansthe sand so that gritty matter is deposited at the discharge end 53. Thesand discharged at the end of the channel 48 is usually the thinnest.

In addition, the water flowing downwardly on the inclined fioor 2| flowsbetween a space confined by this floor and the sloping portion 32 of thedeflecting partition and the side wall I3 and the partition 25 for thethird channel 48. Between the partition 25 and the side Wall I2 there isno partition separating the space between the inclined deflectingpartition and the sloping fioor 2|. On account of the discharge trough53 being located above the horizontal portion 3| and the deflectingpartition and spaced toward the discharge end of the machine from theedge 36 of this partition, the slushing mud does not tend to flowbetween the partition and the floor I 5 but the spray jets in supplyinga quantity of water adjacent the end 35 of the deflecting plate cause athinning out of the mud at this end of the machine and, if anything,tend to form a reverse flow of the diluted mud toward the edge 36 of thedeflecting plate. Therefore, as the bladesof the endless conveyors passunderneath the section 3| of the deflecting plate, the mud becomessomewhat thinner and thereby forms a more complete separation of thesand and mud and allows a more ready depositing by gravity of the sandin the diluted mud. On the lower part of the sloping floor 2| the mud isdiluted to its greatest extent and this prevents the sand being scrapedup from the sloping discharge floor from being stirred up again in themud, as well as facilitates depositing of the sand. Moreover, as abovementioned, the slow movement of the blades of the conveyor is such thatthey do not tend to stir the sand deposited again into the mud ormaintain the mud agitated to such an extent that the sand cannot bedeposited by gravity.

In constructing the tank and channels, it is desirable to have a floorsurface both on the fiat bottom 15 and on the inclined end with a smoothfinish so that the sand may readily be scraped along the bottom and upthe inclined end to the discharge part of this end above the mud level.Also, it is preferable to form the deflecting partition 30 of acomparatively thin metal plate, thus forming a deflecting plate so thatthis may be positioned quite close to the lower run of the conveyor.Substantially all parts of the channels and tank are scraped by theblades of the endless conveyors except the upper surface of thedeflecting plate. The horizontal part of this plate between the firstchannel 44 and the second channel 46 is at the place of reverse flow 55of the mud and, hence, but little sand is deposited on this horizontalportion of the deflecting plate.

The outlet for desanded mud is positioned above the horizontal positionof the deflecting plate, but at this position the mud is Well desandedso but little sand can be deposited on this portion of the plate in thelast or third channel 48.

In connection with my method of operation, this consists in part inusing a scraping action for removing the deposited sand, the scrapingaction being in two of the channels in the direction of the flow of themud and in the center channel in a direction reverse to the flow of themud.

Another feature is that the endless chains or belts on which thescraping blades are mounted, together with the blades, have but littlestirring action when drawn through the mud and deposited sand, duepartly to the low rate of speed and partly to the construction of theendless conveyors. Therefore, the sand already deposited is not stirredinto the mud and the mud is not agitated to enable it to hold the sandin suspension.

Another feature of the method operation comprises the injection of wateron the sand being scraped up the inclined end and the dilution of themud between the end and the floor of the channels adjacent this inclinedend so that any sand held in the mud at the ends of the channelsadjacent the inclined end settles more readily than it would throughthicker or undiluted mud.

An important characteristic of my invention is that the sand in beingconveyed up the inclined discharge end is carried through a passage inwhich the mud is diluted by the spray of injected water 38. Thus the mudin this passage cannot sustain the sand as well as the thicker mud andcauses the mud to allow the settlement of the sand more readily. Also,the mud which would tend to cling to the sand is Washed from this sandand such mud is thereby saved.

My sand and mud separator functions in operation to a certain extent asa classifier in regard to the degree of coarseness or size of the sand.As the sand and mud enters the tank at 53, it flows in the first channelin the direction of the arrow 54 and in this channel the coarse orheaviest sand is deposited, this being scraped out at the discharge endfor the sand. In the middle channel the sand and mud flow in a reversedirection and sand of an intermediate size is deposited, which isscraped out by itself. In the third or final channel the sand and mudflows in the direction of the scrapers and here the lightest or finestsand is deposited, this being removed by a separate scraper.

In the flow of the sand and mud in the various channels, the baffles 6|deflect the flow downwardly, forcing the sand and mud in a downward andin an upward direction at each bafile. This develops a centrifugalaction on the sand, causing the heavier particles to be dischargeddownwardly on to the floor I5, where they may be engaged by thescrapers.

The horizontal section 3| of the partition 30 functions somewhat as askimmer, especially in the last channel of flow. This horizontalpartition forms a positive dividing line between the mud at the surfaceand the sand being scraped through a portion of the mud longitudinallyon the floor l and up the inclined fioor 2| of the last channel. The mudthus skimmed from the surface is discharged at 59 located substantiallytransverse to the horizontal section 3| of the partition. Therefore themud being skimmed off at this last channel is maintained quite separateand distinct from the mud and sand in the lower part of the channel.

The water spray 38 functions to wash the mud from the sand conveyedupwardly on the inclined floor 2!. It also to a certain extent dilutesthe mud in the space between the cross partition 30, the floor l5 andthe inclined floor 2 l On account of diluting the mud in this space, thesand more readily separates from such diluted mud than from theconcentrated mud. Although in the discharge channel the general flow ofthe sand and mud is towards the discharge trough 59, the water spray 38in flowing water underneath the partition 30 gives a slightcounter-current in the space below the partition 30, thus tending tomore thoroughly separate the sand and mud at the last channel before thesand is conveyed upwardly on the inclined floor 2|.

Various changes may be made in the details of construction withoutdeparting from the spirit or scope of the invention as defined by theappended claims.

I claim:

1. In a device as described, an elongated tank having a flat floor andan inclined discharge end, means forming an inlet for mud containingsand at the end remote from the discharge end, a plurality of bafileplates positioned in the tank to extend above the level of liquidtherein, the lower ends of the baflles being spaced above the bottom ofthe tank, whereby sand conveying mud flowing longitudinally of the tankis forced downwardly under each baffle to facilitate separating sandfrom the mud, a conveyor operating along the floor of the tank andupwardly on the discharge end to remove sand deposited in the tank, andmeans to discharge desanded mud adjacent the inclined discharge end ofthe tank.

- 2. In a device as claimed in claim 1, the means to discharge thedesanded mud including a horizontal partition in the tank forming askimming device, said partition being located below the liq- 5 uid levelof the tank, the tank having an overflow with a bottom edge located ator below the said partition.

3. In a device as described, the combination of an elongated tank havinga flat floor and an inlo clined end for the discharge of sand, a seriesof transverse baflie plates positioned in the tank, the upper edgesbeingadapted to be positioned above the level of liquid in the tank and thelower edges spaced above the floor of the tank, a horizontal l5partition adjacent the discharge end of the tank having a horizontalsection above the floor and a sloping section above the inclined end ofthe tank,

said partition with the bottom, sides and inclined end of the tankforming a channel for liquid, said partition forming a skimming device,means forming an inflow for mud containing sand at the end of the tankremote from the inclined end, a conveyor operating along the bottom andup the inclined end of the tank for removal of sand, the said bafllescausing a downward and an upward flow of the mud containing sand tofacilitate separation of sand from the mud,. the tank having an overflowfor desanded mud having its bottom edge located at or above thehorizontal section of the partition of the skimming device.

CHRIS T. CHRISTENSEN.

